4.If a, a, ag.....an are in A.P. and commondifference is d then the value ofsind(coseca, coseca.y + coseca, cosecaz+ ... cosecdn-1 cosecan)will be-(1) seca1 - Secon (2) coseca1 - cosecan(3) cota1-cotan(4) tandi-tanan

If a_1, a_2, a_3,...a_n are in A.P with common difference d !=0 then the value of sind(coseca_1 coseca_2 +cosec a_2 cosec a_3+...+cosec a_(n-1) cosec a_n) will be

If a_1, a_2,a_3,..........., a_n are in A.P. with common difference d, prove that : sin d [cosec a_1 coseca_2+ coseca_2coseca_3+....coseca_(n-1)coseca_n]= cot a_1-a_n .

If a_1,a_2,a_3, ,a_n are in A.P. with common difference d(w h e r ed!=0) , then the sum of series. sind (coseca_1 coseca_2+coseca_2 coseca_3 +....+ coseca_(n-1) cos e ca_n) is equal to cot a_1-cot a_n

If a_1, a_2, a_n are in A.P. with common difference d!=0 , then the sum of the series sind[seca_1seca_2+seca_2seca_3+....+s e ca_(n-1)seca_n] is : a. cos e ca_n-cos e ca b. cota_n-cota c. s e ca_n-s e ca d. t a na_n-t a na

If a_1,a_2,a_3,--- ,a_n are in A.P with common difference d (where d!=0 ) , then the sum of series. sind(cos e ca_1cos e ca_2+cos e ca_2cos e ca_3+ --+cos e ca_(n-1)cos e ca_n) is equal to cota_1-cota_n

if a_(1), a_(2) , a_(3),"……",a_(n) are in A.P. with common difference d, then the sum of the series : sin d [coseca_(1) coseca_(2) + cosec a_(2) cosec a_(3) + "…."cosec a_(n-1) cosec a_(n)] is :

If a_1, a_2, a_n are in A.P. with common difference d!=0 , then the sum of the series sind[seca_1seca_2+(sec)_2seca_3+....+s e ca_(n-1)(sec)_n] is : a.cos e ca_n-cos e ca b. cota_n-cota c. s e ca_n-s e ca d. t a na_n-t a na

If a_1, a_2, a_n are in A.P. with common difference d!=0 , then the sum of the series sind[seca_1seca_2+(sec)_2seca_3+....+s e ca_(n-1)(sec)_n] is : a. cos e ca_n-cos e ca b. cota_n-cota c. s e ca_n-s e ca d. t a na_n-t a na

The value of (cosecA+cotA+1) (cosec A-cot A+1) -2 cosec A is: